Material for the low-temperature soldering of metals



meme-May 2 1,759,279

mime-T m PATENT OFFICE JULES ALFRED BOGNON, OF LEVALLOIS FERRET, FRANCE IATEBIAL FOR THE LOW-TEMPERATURE SOLDERING OF IIE'IIIAIIIIS Io Drawing. Application filed Ju1y'20, 1929, Serial No. 879,883, and in France July 24, 1928.

This invention has for its object the promore, the operation is of very short duration duction of an improved material intended for to'30 seconds) .and as soon as 1t is comthe low-temperature soldering of all kinds of pleted, the parts may be cooled down rapidly .metals and more particularly of aluminum by contact with water and passed along to 5 and its derivatesbe machined.

.The improved material consists primarily I claim as my invention:

of a mixture of-zinc chloride and borax, which A composition for the -low-temperature may be complementd by the addition theresoldering of metals, comprising a mixture of to of such bromides as sodium, aluminum or borax, 18%; zinc chloride, 40% sodium r 10 even ammonium bromide either separately or bromide, 34%; and aluminum bromide, 8%,

in mixtures. The optional admixture of a the aforesaid percentagesbeing by weight. bromide allows the mechanical strength of the In testimony whereof, I aflix my signature. finished work'and the melting point of the JULES ALFRED ROGNON. solder to be set at the desired value dependent upon theuses 'contemplated.

The zinc chloride and the borax,,with or without an additioniof bromides, are mixed in the cold, preferably in an enamelled stoneware container. The constituents must be in a finely pulverized state and, moreover, the

operation must be carried out very rapidly. The product, as s'oo'nas obtained, must be put into a container made of such chemically resistant material as glass-and provided with a tightlyfitting closure to avoid any alteration of the product which is of very hygrometric character.

The proportions of the individual constituents of the mixture may be varied; however the following analysis has been found to gave good results, the parts being given in percentages by weight Borax 18 35 Zinc chloride I 40 Sodium bromide 34 Aluminum or ammonium bromide 8 r p I 100 A product is thus obtained which allows I I y I soldering to be carried on at low temperature (about 0.), thatis, by using a blow-pipe, a small :gas-torch, a spirit torch or even a mere candle, no preparation or cleaning of any kind of either part to be soldered being necessary. It is even unnecesary that a very accurate fitting be provided between the parts to be connected; inall cases, a soldered joint is obtained the-mechanical strength of which 1 is equal to that of a solid part. Further- I 

